The present invention generally relates to ultrasound probes and in particular to ultrasound probe and handle housings and cushions for use with ultrasound probes.
Ultrasonic diagnostic imaging probes generally have been used in the past to image anatomical structures within the body. Ultrasonic probes have been used in the past during non-invasive procedures (such as trans-thoracic probes), during invasive procedures (such as trans-esophageal echocardiography (TEE) probes and trans-vaginal probes), and during surgical procedures (i.e., intraoperative probes).
When using ultrasonic probes, it is important that the hand of the physician using the probe not obscure the site being examined. While the probe is imaging, for example, a physician must be able to accurately determine and maintain the position of the probe while looking at a monitor displaying the information obtained from the probe.
Past intraoperative ultrasound probes have provided, for example in U.S. Pat. No. 5,381,795 to Nordgren et al., an intraoperative ultrasound probe having a transducer section and an angled handle section that form an obtuse angle with respect to one another. The shape of the handle was used in an attempt to permit the physician to grasp the probe without blocking the physician's view of the surgical site. Surgical procedures in which intraoperative probes have been used include vascular surgery and transplant surgery. During vascular surgery, ultrasonic imaging probes can be used to image and diagnose the interior of carotid arteries. In transplant surgery, intraoperative ultrasonic probes can be used to verify successful attachment and function of renal arteries. Intraoperative ultrasound probes are preferably small and as easy to manipulate as surgical instruments.
Past trans-vaginal probes have provided, for example in U.S. Pat. No. 4,742,829 to Law et al., a handle offset from the central axis of the probe. The shape of the handle was used in an attempt to free the space around the entrance of a needle guide to thereby permit manipulation of the needle by hand. The probes disclosed in the above-referenced patents did not, however, present a probe having a multiple-angled handle section.
Past TEE probes have provided, for example in U.S. Pat. No. 5,351,691 to Brommersma, a flexible tube having at one end a probe head. The flexible end part is connected to a housing to allow a probe head to be bent forwards or backwards.
Several problems exist with respect to past ultrasound probes. During examination of organs within the body, particularly during intraoperative examination, the quality of ultrasound images is adversely affected by the presence of a moving organ, due to, for example, blood pulsation. For example, an ultrasound probe may be placed directly on a heart during open heart surgery. The pulsation of the heart applies forces to the ultrasound probe which cause the probe to move up and down and/or side to side and therefore adversely affect the quality of the ultrasound images obtained. The images may be adversely affected because returning ultrasound waves may miss the probe altogether (thereby producing no image) or return when the probe is at a different angle or orientation than when the ultrasound wave was sent (thereby causing an incorrect image to be produced).
Second, ultrasound images are adversely affected by the lack of an effective acoustic coupling due to the fixed (usually flat) transducer or probe surface and the curved or irregular shape of an anatomic structure, such as a heart, artery or other organ (especially during intraoperative examination). When a flat probe is placed against the curved or irregular surface of an anatomic structure, only a portion of the probe actually contacts the anatomic structure. When this occurs, air is located between the non-contacting portion of the probe surface and the anatomic structure. Ultrasonic waves travel at different speeds in air than in the anatomic structure. Because of the different speeds at which ultrasonic waves travel, the ultrasonic waves refract (i.e., bend sharply) when they enter and leave the anatomic structure. Because of this refraction or bending, the returning ultrasound waves may either appear to emanate from an incorrect location or miss the probe altogether. The existence of various, unpredictable air pockets between the probe and anatomic structure may be referred to as the lack of an effective acoustic coupling. A smaller number of air pockets between the probe surface and anatomic structure corresponds to a more effective acoustic coupling.
Third, when using past ultrasound probes, it is difficult to obtain steady probe contact with an organ while not deforming the organ or its blood flow, especially during intraoperative examination. Organ deformation occurs because past ultrasound probes placed a rigid probe surface against the soft organ tissue. In order to achieve an effective acoustic coupling, a probe user may firmly press the probe against the anatomic structure sought to be imaged. This deformation adversely affects ultrasound image quality because an anatomic structure sought to be imaged may be deformed to an unnatural shape or the velocity of blood flow may be altered due to deformation. The alteration of blood flow may be a particular problem where blood flow pattern and/or velocity are sought to be imaged.
Past ultrasound technology has not presented an ultrasonic probe that can avoid the aforementioned problems of organ movement during intraoperative ultrasound examination, the lack of an effective acoustic coupling, and deformation.
A need has long existed for such a probe. A further need remains for an improved ultrasonic probe housing that enables a physician to accurately determine and maintain the position of the probe during use. A need also remains for an improved ultrasonic probe housing that allows the physician to move the probe while maintaining its orientation without having to view the probe to ensure it is oriented properly. It is an object of the present invention to meet these needs.